Shallow-water Holothuroids (Echinodermata) of Kosrae, Eastern Caroline Islands

Abstract

Line transects and qualitative surveys were used to determine species composition and abundance distributions of holothuroids on the fringing coral reefs of Kosrae, Federated States of Micronesia. On the reef flats, in a total sample area of 2982 m2 , 9383 holothuroids, comprising 13 species, were recorded. An additional 13 species were recorded off the transects between depths of 0 and 30 m. Species richness varied considerably between sites and physiographic zones and was significantly correlated with reef-flat width. Holothuria (Halodeima) atra Jaeger was the most abundant species recorded, composing 92.1 % of the holothuroids on the transects. Other species were considerably less abundant: H. (Platyperona) difficilis Semper, H. (Thymiosycia) hilla (Forsskfll), Afrocucumis africana Semper, and Actinopyga mauritiana Quoy & Gaimard were 6.1, 0.8, 0.3, and 0.2% of the enumerated taxa, respectively. For all other species, each composed <0.1% of the fauna. Kosrae had very low densities of most commercially valuable holothuroids; only two marketable species, Actinopyga mauritiana and H. (Metriatyla) scabra Jaeger were found there in relative abundance. Twenty-eight species of holothuroids are now reported from Kosrae.